This invention relates to a surface mounter and more particularly to an improved mechanism for placing articles on a work piece.
A wide variety of devices have been proposed for picking a work piece from a supply station and placing it at a desired location at a work station. For example, there are provided a number of various devices called "surface mounters" which will pick discreet and minute electrical components such as integrated circuits, resistors, condensers or the like and mounting them on a surface of a substrate such as a printed circuit board.
Generally the way these devices operate is that the substrate or circuit board is moved along a conveyor to a specific work station. A gripping device, which normally operates by vacuum, will pick up the electrical component from a feeder and move in the X and Y axes to locate the component above the desired location on the substrate and then deposit it on the substrate. The way these devices are normally constructed is that there is a first frame or carriage that is supported for movement in the X-X direction and a second carriage that is supported on the first carriage and moveable relative to it in the Y-Y direction. By moving the two carriages either together and/or relative to each other, the desired X-Y location for pick-up and deposit can be determined. However, this type of device is rather cumbersome and because of the dual carriage arrangement its speed tends to be slow and the number of devices which can be utilized to function at a single work station are limited.
Various devices have been proposed for attempting to solve these problems and one such device is shown schematically in FIG. 1, which figure comprises a top plan view of this type of device and which is illustrated primarily in schematic form. In this device, a mounter 21 is supported for movement along an X-X axis by means of a guide rail 22. The mounter 21 is adapted to pick up work pieces from selective feeding stations 23 and/or 24 and deposit them on a substrate P, such as a printed circuit board, which is mounted for movement along a Y-Y axis on a support shaft 25. As may be seen from this figure, if the number of feeder stations is to be increased or the size of the feeder stations increased, this must be done in the X-X plane and thus there is further delay in having the feeder move to the station where the substrate is located. Another type of prior art device is shown in FIG. 2, which also comprises a top plan view similar to FIG. 1, and includes a feeder 23 on which components are moved for depositing on the substrate P by a rotary mounting head 31. The substrate P are moved in the X-Y direction by suitable support rails. The disadvantage with this type of construction is that it is quite large and the mechanism becomes complicated for coping with multi-production.
It is, therefore, a principal object of this invention to provide an improved high speed surface mounter.
It is a further object of this invention to provide a high speed surface mounter that permits rapid movement and accurate placement of a plurality of different types of work pieces at different locations on a plurality of different types of substrates.
As has been noted, the components to be mounted are picked up by a pick-up device, normally one which is vacuum operated. It is the conventional practice to mount these pick-up devices on a pneumatic cylinder which moves from a position wherein the work piece is picked up to a retracted position and then back to a position for mounting the components on the substrate. The disadvantage with this type of construction is that the pneumatic cylinder which moves the head has generally fixed stroke and its speed during movement cannot be controlled. As a result, when there are variations in the height of the various components, such as the location of the substrate, the components may be mounted on the substrate with shock. In addition, the versatility of the system is limited.
Therefore, it is a further object of this invention to provide an improved mounter arrangement for selectively gripping the components and which has versatility in its movement.